地下气化过程中煤系沉积岩热物理性能试验研究

Thermo-physical properties experimental study of sedimentary rocks of coal measures in underground gasification process

利用GHC-Ⅱ型比热容测试仪、DRX-Ⅱ型导热系数测定仪等仪器,对乌兰察布地下气化煤层顶板泥岩、砂质泥岩、细砂岩、粗砂岩及粉砂岩等5种沉积岩体进行了50~1000℃范围内的高温物理试验研究,分析了不同温度梯度下的比热容及导热系数随温度的变化规律,并用多项式函数对5种岩样的导热系数测定结果进行了拟合,得到了导热系数与温度的拟合关系式。试验结果表明,5种岩样的比热容值随着温度的升高呈现下降趋势,在100~400℃范围内,5种岩样的比热容值下降趋势较为明显;顶板泥岩等5种岩性岩样的导热系数值随着温度的升高呈现下降趋势,随着温度的升高,粗砂岩导热系数值变化最大,由50℃时的1.412W/（m·K）下降至1000℃时的0.900W/（m·K）,减小了36.3%;随着温度升高,粉砂岩导热系数值变化最小,其值由50℃时的1.200W/（m·K）下降至1000℃时的0.901W/（m·K）,减小了24.9%。上述结果可为研究煤炭地下气化空间温度场分布提供必要的数据。

Using GHC-II type specific heat capacity tester and DRX-II type thermal conductivity measuring instrument,high temperature physics experimental study was carried out in a range of 50~1000℃for 5 kinds of sedimentary rock,including roof mudstone,sandy mudstone,fine sandstone,coarse sand stone and siltstone taken from Wulanchabu underground gasification coal seam.The variation of specific heat capacity and thermal conductivity coefficient with temperature under different temperature gradients condition was analyzed.A polynomial function was used to fit the experimental results of 5 samples′thermal conductivity coefficient,and the fitting relationship between thermal conductivity coefficient and temperature was obtained.Experimental results indicate that specific heat capacity of five kinds of rock samples decreased with the increase of temperature.In the range of 100~400℃,the specific heat capacity of five samples decreased obviously.Thermal conductivity coefficient of 5 kinds of rock samples presents decreasing trend with the increase of temperature.As temperature increases,thermal coefficient of coarse sandstone decreases from 1.412 W/（m·K）at50℃to 0.900 W/（m·K）at 1000℃,which is reduced by 36.3%.Thermal conductivity coefficient of siltstone decreases from 1.200 W/（m·K）at 50℃ to 0.901 W/（m·K）at 1000℃,which decreases24.990% with the increase of temperature,that is minimum value in 5 kinds of samples.Above results can provide the necessary data for the study of the spatial temperature field distribution of coal underground gasification.